Automatic control device.



c. F. JOHNSON.

AUTOMATIC CONTROL DEVICE.

APPLICAT'ION FILED JUNE l. l9`l4. y

Patented Nov. 30, 1915.

"UNrrnD sra'rns PATENT- ormon- CARL F. OI-INSON, 0F MILWAUKEE, WISCONSIN, ASSIGNO'R TO JOHNSON SERVICE COMPANY, 0F MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

AUTOMATIC CONTROI DEVICE.

Specification of Letters Patent.

Continuation of application Serial No. 723,899, filed October 4, 1912. T his application led June 1, 1914.

Serial No. 842,225.

To all 'whom t may Vconcern Be it known that I, CARLF. JOHNSON, a

4citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain 1 new and useful Improvements in Automatic Control Devices, of which the following is a specification. Y

This application is filed as a continuation of and substitute for my application Serial Number 723,899, filed October 4, 1912 andv erally, the prior application being possibly restricted to thermostats by tacit limitations in its claims. As stated in the supplemental oath filed with this application 'the entire subject-matter of the present application was in fact a part of the original invention.

'Ihe present invention relates -to thermostats, hygrostats and kindred automatic control devices, and is particularly intended for use in systems for controlling temperature tion of this control valve mechanism usuallyv -admits or'exhausts ai'r to and from a secondor humidity, such as the Johnson system.

In this system as commonly constructed for temperature regulation .the thermostatic den.

vice consists of a bimetallic thermostatic bar which moves under the influence of temperature changes to open and close a leak port. Through this leak port fluid under suicient to cause a control valve operatingl motor to remain inert, but when the leak port is closed thls motor is moved to shift the control valve mechanism. The operaary motor which is directly connected to dampers or any other mechanisms which are to be controlled in response to temperature variations. All such prior structures have required yas an element thereof, a quick throw device v between the motor and the control valve to move the control valve suddenly from full open to full closed position, and this has resu, ted in considerable compllcation. The s e is true of the devices for controlling humidity, the essential distinction being the use of a dier'ent responsive element andthe control of adiHerent type of mechanism by the device.

The purpose of the present invention is to avoid the use'of such .quick throw mechani-sm and to secure a thermostat, hygrostat or the like, which is simpler in construction and quicker in action than any heretofore known.

I shall describe the invention as embodied in a thermostat intended for use in the Johnson system, though capable of use in other systems in its present or in slightly modified forms. show the invention as applied to a hygrostat. The characteristic of the device is the use of a shifting leak port by which I secure a suiiiciently quick opening and closing action of the leak valve 'to avoid the necessity of `the quick throw mechanism hitherto considered essential. The -principal mechanical features of such a device are illustrated in the accompanying drawings, in which,

Figure l is a vertical section through the l Patented Nov. 3o, 1915.-

thermostatic valve showing the position assumed by the parts when the leak port is open; Fig. 2 is a view similar to Fig. 1,

showing 'the position the parts assume when the leak port is closed; Fig. 3 isa similar view of a modified structure, showing the leak port open; and Fig. 4 is a similar view of a hygrostat embodying my invention.

In the drawings, 1 represents' the wall plate or frame of the thermostatic ,device and 2 is the front or cover plate thereof, the castings 1 and 2 formin a hollow body which is .divided into various chambers by means of three diaphra ms 3, 4, and 5. The diaphragm 3 carries tube 'or vent valve member 6, which is mounted for longitudinalmovement through the front plate 2, such movement being limited by a shoulder 7 and the clamping nuts 8 which clamp the tube 6 tothe diaphragm. Usually a range of movement of one or two one-thousandths of an inch is suicient. In the device shown in Figs. 1 and 2 the diaphragm 3 is made ofV thin? resilient metal and is designed tourge the-leak tube 6 inward but to allow it to move outward under moderate pressure in the chamber 9 to the left of the diaphragm 3. The chamber 10 to the right of the diaphragm 3 is open to ast thereto the leakv phragm 4 which is relatively flexible and may be made of any suitable material such as leather'or rubber fabric. The chamber 411 is open to the atmosphere through an eX-v haust port 12 and may be termed the exhaust chamber of the device. Upona riseof pressure in the chamber 9 the diaphragm 4 would be forced to the left and would bear against the end of the stem of a valve member 13. This valve member 13 is formed with a longitudinal exhaust port 14, andy is guided in a slide-way 15. The valve member 13 is clamped to diaphragm 5, as shown, and when in its right-hand position as viewed in the drawing, it seals a supply port 16, formed in the casting 1.

Air is constantly supplied under pressure through a supply port 17 which has two branches 18 and 19. The branch 19 is provided witha needle valve 20 to adjust the rate of flow, the needle valve 20 being sealed against leakage by means of a screw plug 21, as shown. A |The branch 19 leads to the chamber 9 which is vented to the atmosphere through the leakage tube 6 when the ldevice is'in the position shown in Fig. 1. The branch 18\leads to the space 22 at the left of diaphragm 5 and at the right of the supply port 16, which opens into the control pipe 23 connected'to the motor to be operated. This commonly is the damper motor used in various regulating systems.

The parts are so arranged that when the diaphragm 4 moves to the left it first seals the exhaust port 14 and then moves the valvey member 13 bodily to the left, opening supply port 16. Pressure acting against the left side of diaphragm 5 constantly urges it to the right and when the pressure in chamber 9 to the right of diaphragm 4 falls,

valve 13 will be allowed to move to the right and seal .the port 16, after which the air will be vented from the pipe 23 through the port 14, chamberll and port 12. The

valve 13 with its co-actingjparts formsmerelyl a supply and exhaust valveC adapted to admit pressure to and release it from a secondary motor connected to the pipe 23.

I contemplate the substitution for-this valve of any suitable mechanism operable" by the diaphragm 4 or similar primary motor and adapted properly to control the operation of -a `secondary motor.

v24 is a bi-metallic thermostatic bar characteristic of the Johnson thermostats, the bar bending under changes of temperature to yopen and close the leakage ,tube 6,'by

means of a valve Aface 25, carried on the end of the( bar 24. Other thermosatic devices, well known in the art, may gbe subtually vent the chamber 9 and prevent any accumulation of pressure therein while the leak tube is open. Consequently diaphragm n 4 stands to the right and permits a closing of supply port 16 and a\venting of pressure from pipe 23 and its connected motor, as -already explained. It is to be observed that the resilient diaphragm 3 maintains the leak tube 6 inl its inner or left hand position when the parts are in the position described. If

now, throughia change of temperature the bar 24 moves valve face 25 toward. leak tube 6, and even before it has completely sealed the leak tube 6, thefollowing action takes place:

. The retardation of flow-.through theleak tubel will cause a rise of pressure in chamber 9 y which, acting upon diaphragm 3, willy force the same to the right thus tightly sealing the leak tube againstvalve face 25. Immediately this sealing has taken place pressure will rapidly rise in4 chamber9, forcing diaphragm 4 to the left so as to seal the port 14 and movevalve 13 to open port 16. Air

will thereupon flow throughpipe 17, chamber 22 and port 16 to the'pipe 23 so as to operate the damper motor or other equivalent device. Upon a subsequent change of temperature in the opposite direction a very slight movement of valve face 25 away from `leak tube 6 will initiatea venting of chamber 9 sufficient to cause diaphragm 3 to move the leak tube 6 to the left. Such movement causes a rapid discharge from the chamber 9 and a rapid movement of diaphragm 4 to the right which as will be apparent closes f supply port 17 and opens exhaust port 14, allowing the damper motor tomove in thereverse direction.` In the construction abovese't` relied upon pressure on diap move the valve 13 to the right and upon the resiliency of diaphragm 3 to move leak tube 6 to the-left.

In Fig. 3 I have shown a modilied'device lin which the valve 13 moves through a stuff- M ragmI 5 to ing box-:26 instead of being attached 'to a' diaphragm 5, the springA 27 being added to forcethe valve to the right. I also illustrate in this 'ligure a non-metallic f lexiblediaphragm 3 with which I use a spring 28 to n urge the leak tube 6 to the left.`

In F ig. 4 I illustrate the application of -the invention toa hygrostat. The only l change is the substitutionof a hygrostatic the framel a pairv of forwardly projecting llugs 29 are provided. To these is pivoted a weighted saddle 30 which carries an upstanding valve bar 31 to coact with the leak tube 6. `Thesaddle 30. is so weighted as to i swingA the valve bar 31 in a direction'to seal against :the tube 6.- Moun-ted in a socket 32 lin the frame lis an outwardly projecting hygrostatic element 33, which may consist' of wood cut across the grain or any other material which willchange its length with changes of atmospheric humidity. An adjusting screw 34 threaded in the valve bar 31 bears Jagainst the end of the hygrostatic element 33,`the screw 34 permitting the desired adjustment of the valve bar'31 with reference tothe leak tube 6. Changes of atmospheric humidity will move the valve bar 31 to control the leak tube 6 and cause the actuation of the device in the manner already described.

From the above description itl will be apparent that the prime distinction between my device andthe prior art is that I provide a quick acting vent valve which moves vso promptly from full open to full closed position as to\ obviate the necessity of a quick throw device between the control diaphragm or primary motor and the control mechanism. This not only avoids thecomplication incident to sucha quick throw device, but' provides a valve which is much more sensitive than those heretofore constructed and which has noneutral position. The essential invention, therefore, resides in the quick acting thermostatic vent valve in combination with a1 primary pressure motor, Asuch as the diaphragm 4. This primary motor may', asA shown, actuate a control valve 'to regulate the operation of a secondaryvfluid pressure motor, or it may,

actuate an other type of control mecha nism adap d to control the operation of any other corresponding type of secondary motor, such devices'being known equivalents in thefart: lInfact the primary motor may be used-.to operate a wide range of devices, and I contemplate such use. It is also to be notedl that the vent` valve might take diiierent forms which will readily suggest themselves, the essential feature being that the valve consists of co-acting elements, one of which is movable. by a thermostatic, hygrost-atic or other .responsive element affected -by changes of atmospheric condition, and the' other of which is movedin a pressure in the chamber 9, and in an' openbut contemplate the substitution of well Y known equivalents where they secure the same effect and lie within the scope of my inventive idea.

I use the term abutment in the claims to include such devices as pistons, diaphragms, etc., all of which are known equivalents in the art.

I use'the term responsive element in the'claims to include thermostaitic, hygrostatic or other elements which are subject to a change of form in response to changes in atmospheric conditions. l

Having thus described my` invention, what I claim is nl. The combination vof a fluid pressure motor; a source of iu'id pressure leading thereto; a vent valve for said motor adapted to bemoved by pressure in said motor; and a closure for said valve located in line therewith having automatic actuatingmeans responding to changes in atmospheric condition, Asaid valve being adapted to move toward said .closure upon a rise of pressure in said motor, whereby alquick sealing is eected.

so i 2. The combination of a fluid pressure motor; a source of fluid pressure leading thereto; a vent valve for said motor adapted to move under variations of pressure in said motor; and a closure for `'said valve located in line therewith having automatic actuating means responding to changes in atmospheric condition, said valve being adapted to move away from said closure upon a fall of pressure in said motor by a quick venting is secured.

3. The combination of a control. mechanism for a motor; a fluid pressure actuated whereabutment vadapted to operate 4said control mechanism; a source of'fluid pressure' leadlng thereto; .a .vent valve mechanism resppnsive to changes in atmospheric condition adapted to vent vfluid pressure acting on said abutment; and a pressure actuated device subject to the fluid pressure acting on said abutment and adapted to coact with the vent valve mechanism to close the same upon an initial increase of fluid pressure l and to open the same upon an initial decrease of pressure.

` 4. The .comblnatlon' of a control mechanism for a motor; a Huid actuated abutment adapted to operate said control mech- ,anismg asource of fluid pressure leading abutment and adapted upon an initial increase of such pressure to close said vent valve, and upon any initial decrease in said pressure to open said vent valve.

5. The combinationof a control mechanism adapted to control the operation `of' a motor; a fluid pressure actuated abutment adapted to operate said control mechanism; a source of fluid pressure leading thereto; a movable valve member having a port adapted tok vent pressure from said abutment; a second movable valve member adapted to .coact with the first movable valve member to control the vent port therein; a responsive element operatively connected to move one valve member in response to variations inv atmospheric condition; and a pressure actuated device subject to the pressure acting on said abutment and adapted to coact Withthe otherv valve memberto move the same in a closing direction upon an initial increase in` such pressure and in an vopening direction upon an initial decrease in such pressure.

6. The combination of a control mechanism adapted to control the operation of a motor; a fluid pressure actuated abutment adapted to operate said control mechanism; a source of fluid pressure leading thereto; a movable valve member having a. port adapted to vent pressure from said abut- 4ment; a second movable valve member adapted to coact with the first movabile valve member to control the vent port therein; a responsive element operatively connected to move one valve member in response to variations in atmospheric condition; and a resilient diaphragm sub-ject to the pressure acting on said abutment and adapted to coact withathe other valve member to move the same in a closing direction upon an initial increase in such pressure and in an opening direction upon an initial decrease therein.

7. The combination with a control mechanism including a pressure chamber and a n source of fluid pressure leading thereto; of

a valve member having a sealing face; a responsive element adapted to move said valve member; a vent tube adapted to vent pressure .from said chamber and mounted to have a limited movement toward and from said sealing face to close and open said tube; an abutment subject to pressure inl said chamber and connected to said vent tube to move/the same toward said sealing face; and resilient means opposing such movement.

8. The combination With a control mechanismincluding a pressure chamber and a source of fluid pressure leading thereto; of afvalve member having a sealing face; a responsive element adapted to move said valve member; avent tube adapted to vent pressure from said chamber and mounted to have a limited movement toward and from said sealingy facegto close and open Saidtube; and a resilient diaphragm-connected@ to said tube s'ibjectto'tlfie p.ressure in said' chamber and adapted to urge sa1d tube toward said sealing face in opposition to the resiliency of said diaphragm. s

9. The combination With a control mechanism including a pressure chamber and a source of fluid pressure leading thereto; a movable valve having a sealing face; a responsive element adapted to move said. valve; a vent tube adapted to vent pressure from said chamber and mounted to have a limited movement toward and from said sealing face; and a mechanism subject to pressure in said chamber, connected to said vent tube and adapted to move the latter into sealing engagement With said sealing face upon an initial rise of pressure in said chamber, and out of such engagement upon an initial fall' of such pressure.

10. A vent valve for a pressure motor control device comprising a vent tube mountto said tube and subject to thepressure to be vented, urging said tube .toward said sealing face; and resilient means acting in opposition to the pressure on said abutment.

l1. A vent .valve for a pressure motor con- .trol device comprising a vent tube mounted to have limited longitudinal movement; a responsive element having a sealing face movable under changes of atmospheric condition into and out of sealing relation with the end of said tube; and a resilient diaphragm connected to said tube and subject to the pressure to be vented, acting to move said tube toward said sealing face in opposition to the resiliency of' the diaphragm.

12. A vent valve for a pressure motor control device comprising a valve member having a vent port; a second valve member coacting with the first tocontrol said vent port; 'a responsive element adapted to move one valve member in response to variations in atmospheric condition;` and a pressure actuated device subject to the pressure to be vented and adapted upon a rise of such pressure to move the other valve member toward closed position and upon a fall of such pressure toward open position. 13. In a control device a valve adapted alternately to supply and exhaust fluid pressure to a secondary device; means urging said valve toward exhaust position; a valve actuating motor adapted under pressure to force said valve from exhaust to supply position: a responsive element having a sealing face adapted to move in accordance with variations of atmospheric condition; a vent tube .adapted to vent pressure from said motor and to move into and out of sealing relation with said sealing face; and a pressure actuated device, subject to the pressure in said motor, connected toy said vent tube and adapted to move the latter toward alternately to supply and exhaust uid pressure to a secondary' device; means urging said valve toward exhaust position; a valve actuating motor adapted under pressure to force said valve from exhaust to supply position; a responsive element having a sealing face adapted to move in accordance with variations of atmospheric condition; a vent tube adapted to vent pressure from said motor and to move into and out of sealing relation with said sealingface; and a resilient diaphragm, subject to the pressure in said motor, connected to said vent tube and adapted to move the latter toward said sealing face upon an increase of such pressure and away from said sealing face upon a decrease of such pressure.

15. A vent valve for a Huid pressure con trol device including a member having a vent port; a valve member (1o-acting therewith t0 control. said port; a responsive ele ment adapted to movesaid valve member in response to variations in atmospheric con dition; and a pressure actuated device subject'to the pressure to be vented, and adapted upon a rise of such pressure to effect a closingof the vent port by relative mowment of the valve member and the port.

In testimony whereof l have signed niv name to this specification in the` pres-ence of 1 two subscribing witnesses.

. CARL F JOHNSON. Witnesses EDWIN L. JAUKE, GEORGE BRUESER. 

